<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgl - cloth simulation</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<style>
			body {
				font-family: Monospace;
				background-color: #000;
				color: #000;
				margin: 0px;
				overflow: hidden;
			}

			#info {
				position: absolute;
				padding: 10px;
				width: 100%;
				text-align: center;
			}

			a {
				text-decoration: underline;
				cursor: pointer;
			}

		</style>
	</head>

	<body>
		<div id="info">Simple Cloth Simulation<br/>
			Verlet integration with relaxed constraints<br/>
			<a onclick="wind = !wind;">Wind</a> |
			<a onclick="sphere.visible = !sphere.visible;">Ball</a> |
			<a onclick="togglePins();">Pins</a>
		</div>

		<script src="../build/three.js"></script>

		<script src="js/Detector.js"></script>
		<script src="js/controls/OrbitControls.js"></script>
		<script src="js/libs/stats.min.js"></script>

		<script src="js/Cloth.js"></script>

		<script type="x-shader/x-fragment" id="fragmentShaderDepth">

			#include <packing>

			uniform sampler2D texture;
			varying vec2 vUV;

			void main() {

				vec4 pixel = texture2D( texture, vUV );

				if ( pixel.a < 0.5 ) discard;

				gl_FragData[ 0 ] = packDepthToRGBA( gl_FragCoord.z );

			}
		</script>

		<script type="x-shader/x-vertex" id="vertexShaderDepth">

			varying vec2 vUV;

			void main() {

				vUV = 0.75 * uv;

				vec4 mvPosition = modelViewMatrix * vec4( position, 1.0 );

				gl_Position = projectionMatrix * mvPosition;

			}

		</script>

		<script>

			/* testing cloth simulation */

			var pinsFormation = [];
			var pins = [ 6 ];

			pinsFormation.push( pins );

			pins = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ];
			pinsFormation.push( pins );

			pins = [ 0 ];
			pinsFormation.push( pins );

			pins = []; // cut the rope ;)
			pinsFormation.push( pins );

			pins = [ 0, cloth.w ]; // classic 2 pins
			pinsFormation.push( pins );

			pins = pinsFormation[ 1 ];


			function togglePins() {

				pins = pinsFormation[ ~~ ( Math.random() * pinsFormation.length ) ];

			}

			if ( ! Detector.webgl ) Detector.addGetWebGLMessage();

			var container, stats;
			var camera, scene, renderer;

			var clothGeometry;
			var sphere;
			var object;

			init();
			animate();

			function init() {

				container = document.createElement( 'div' );
				document.body.appendChild( container );

				// scene

				scene = new THREE.Scene();
				scene.fog = new THREE.Fog( 0xcce0ff, 500, 10000 );

				// camera

				camera = new THREE.PerspectiveCamera( 30, window.innerWidth / window.innerHeight, 1, 10000 );
				camera.position.x = 1000;
				camera.position.y = 50;
				camera.position.z = 1500;
				scene.add( camera );

				// lights

				var light, materials;

				scene.add( new THREE.AmbientLight( 0x666666 ) );

				light = new THREE.DirectionalLight( 0xdfebff, 1.75 );
				light.position.set( 50, 200, 100 );
				light.position.multiplyScalar( 1.3 );

				light.castShadow = true;

				light.shadow.mapSize.width = 1024;
				light.shadow.mapSize.height = 1024;

				var d = 300;

				light.shadow.camera.left = - d;
				light.shadow.camera.right = d;
				light.shadow.camera.top = d;
				light.shadow.camera.bottom = - d;

				light.shadow.camera.far = 1000;

				scene.add( light );

				// cloth material

				var loader = new THREE.TextureLoader();
				var clothTexture = loader.load( 'textures/patterns/circuit_pattern.png' );
				clothTexture.wrapS = clothTexture.wrapT = THREE.RepeatWrapping;
				clothTexture.anisotropy = 16;

				var clothMaterial = new THREE.MeshPhongMaterial( {
					specular: 0x030303,
					map: clothTexture,
					side: THREE.DoubleSide,
					alphaTest: 0.5
				} );

				// cloth geometry
				clothGeometry = new THREE.ParametricGeometry( clothFunction, cloth.w, cloth.h );
				clothGeometry.dynamic = true;

				var uniforms = { texture:  { value: clothTexture } };
				var vertexShader = document.getElementById( 'vertexShaderDepth' ).textContent;
				var fragmentShader = document.getElementById( 'fragmentShaderDepth' ).textContent;

				// cloth mesh

				object = new THREE.Mesh( clothGeometry, clothMaterial );
				object.position.set( 0, 0, 0 );
				object.castShadow = true;
				scene.add( object );

				object.customDepthMaterial = new THREE.ShaderMaterial( {
					uniforms: uniforms,
					vertexShader: vertexShader,
					fragmentShader: fragmentShader,
					side: THREE.DoubleSide
				} );

				// sphere

				var ballGeo = new THREE.SphereGeometry( ballSize, 20, 20 );
				var ballMaterial = new THREE.MeshPhongMaterial( { color: 0xaaaaaa } );

				sphere = new THREE.Mesh( ballGeo, ballMaterial );
				sphere.castShadow = true;
				sphere.receiveShadow = true;
				scene.add( sphere );

				// ground

				var groundTexture = loader.load( 'textures/terrain/grasslight-big.jpg' );
				groundTexture.wrapS = groundTexture.wrapT = THREE.RepeatWrapping;
				groundTexture.repeat.set( 25, 25 );
				groundTexture.anisotropy = 16;

				var groundMaterial = new THREE.MeshPhongMaterial( { color: 0xffffff, specular: 0x111111, map: groundTexture } );

				var mesh = new THREE.Mesh( new THREE.PlaneBufferGeometry( 20000, 20000 ), groundMaterial );
				mesh.position.y = - 250;
				mesh.rotation.x = - Math.PI / 2;
				mesh.receiveShadow = true;
				scene.add( mesh );

				// poles

				var poleGeo = new THREE.BoxGeometry( 5, 375, 5 );
				var poleMat = new THREE.MeshPhongMaterial( { color: 0xffffff, specular: 0x111111, shininess: 100 } );

				var mesh = new THREE.Mesh( poleGeo, poleMat );
				mesh.position.x = - 125;
				mesh.position.y = - 62;
				mesh.receiveShadow = true;
				mesh.castShadow = true;
				scene.add( mesh );

				var mesh = new THREE.Mesh( poleGeo, poleMat );
				mesh.position.x = 125;
				mesh.position.y = - 62;
				mesh.receiveShadow = true;
				mesh.castShadow = true;
				scene.add( mesh );

				var mesh = new THREE.Mesh( new THREE.BoxGeometry( 255, 5, 5 ), poleMat );
				mesh.position.y = - 250 + ( 750 / 2 );
				mesh.position.x = 0;
				mesh.receiveShadow = true;
				mesh.castShadow = true;
				scene.add( mesh );

				var gg = new THREE.BoxGeometry( 10, 10, 10 );
				var mesh = new THREE.Mesh( gg, poleMat );
				mesh.position.y = - 250;
				mesh.position.x = 125;
				mesh.receiveShadow = true;
				mesh.castShadow = true;
				scene.add( mesh );

				var mesh = new THREE.Mesh( gg, poleMat );
				mesh.position.y = - 250;
				mesh.position.x = - 125;
				mesh.receiveShadow = true;
				mesh.castShadow = true;
				scene.add( mesh );

				// renderer

				renderer = new THREE.WebGLRenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				renderer.setClearColor( scene.fog.color );

				container.appendChild( renderer.domElement );

				renderer.gammaInput = true;
				renderer.gammaOutput = true;

				renderer.shadowMap.enabled = true;

				// controls
				var controls = new THREE.OrbitControls( camera, renderer.domElement );
				controls.maxPolarAngle = Math.PI * 0.5;
				controls.minDistance = 1000;
				controls.maxDistance = 7500;

				// performance monitor

				stats = new Stats();
				container.appendChild( stats.dom );

				//

				window.addEventListener( 'resize', onWindowResize, false );

				sphere.visible = ! true;

			}

			//

			function onWindowResize() {

				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();

				renderer.setSize( window.innerWidth, window.innerHeight );

			}

			//

			function animate() {

				requestAnimationFrame( animate );

				var time = Date.now();

				windStrength = Math.cos( time / 7000 ) * 20 + 40;
				windForce.set( Math.sin( time / 2000 ), Math.cos( time / 3000 ), Math.sin( time / 1000 ) ).normalize().multiplyScalar( windStrength );

				simulate( time );
				render();
				stats.update();

			}

			function render() {

				var p = cloth.particles;

				for ( var i = 0, il = p.length; i < il; i ++ ) {

					clothGeometry.vertices[ i ].copy( p[ i ].position );

				}

				clothGeometry.computeFaceNormals();
				clothGeometry.computeVertexNormals();

				clothGeometry.normalsNeedUpdate = true;
				clothGeometry.verticesNeedUpdate = true;

				sphere.position.copy( ballPosition );

				camera.lookAt( scene.position );

				renderer.render( scene, camera );

			}

		</script>
	</body>
</html>
